Electrical circuits Flashcards
What are circuit diagrams used to show?
Circuit diagrams are used to show electrical circuits.
When will an electric current flow?
When there is a completely closed circuit, an electric current will flow.
What is an electric current?
An electric current is a flow of charge.
What is the charge due to in copper wires?
In copper wires, the charge is due to negatively charged electrons.
What is electric current measured in?
Electric current is measured in amperes (A), using an ammeter connected in series.
What are the electrons in the circuit attracted to?
The electrons in the circuit are attracted to the positive terminal of the battery, but conventional current flows from positive to negative.
What are series circuits like?
In series circuits, components are connected end to end in a single loop. The current is the same all the way round the series circuit. An ammeter placed at points A and B will show the same reading.
What are parallel circuits like?
In parallel circuits, the components are connected across each other. The current will split at the junction X and re-join at junction Y.
What is the unit of electric charge?
The unit of electric charge is the coulomb (C). An electron carries a tiny amount of charge - only - 1.6 x 10 to the power of -19 C.
How do you work out electric current?
electric current (A) = electric charge (C) divided by time (s)
What gives the energy in a circuit?
The cell or battery in a circuit gives energy to the electrons so that they can transfer energy to the components in the circuit.
What is chemical energy converted into?
The chemical energy in the cell is converted to electrical energy of the electrons.
What does a voltmeter do?
A voltmeter measures the amount of energy transferred in a component. It is connected in parallel across the component.
In a series circuit, what does the voltage across individual components add up to?
In a series circuit, the voltage across individual components adds up to the voltage across the power supply (V = V1 + V2)
In parallel circuits, what is the voltage across each component the same as?
In parallel circuits, the voltage across each component is the same as the voltage across the power supply (V = V1 = V2)
